Why Some People Thrive in Winter

I do not know if “winter people” actually exist. All I know is that I’m definitely not one.

I view this wretched season’s icy winds, frozen slush, and musty parkas not as a natural and unavoidable part of life in the American North, but as a personal attack on me. To be clear, this is not darkness-induced seasonal affective disorder, or SAD. This is me being MAD that it’s not 80 degrees out. I do not ever feel “hygge.” There’s usually a day in mid-January when I grouse that the weather forecast is, yet again, “38 and raining,” and angrily order another pair of those impotent touchscreen gloves that I keep losing. Then I realize there’s still more than a month to go.

This attitude comes as a shock even to me, since I was born in Russia and lived in St. Petersburg until I was 3. This means that not only am I failing at winter, I’m failing my countrymen.

I’ve long wondered if I can blame my inability to tolerate cold temperatures on West Texas, where I grew up, and where people cheerfully ask “hot enough for ya?” as the sun slowly grills your corneas. The question in my hometown was never whether it was too cold to go outside, but too hot. Clothing strategies centered around covering up the most skin without sous-viding in your own sweat. You would don the thinnest t-shirt, run through the neighbor’s sprinklers, and hope you made it to your friend’s house before dehydration set in.

When I came to D.C. for college, I bought my first winter coat. I also seriously considered transferring to a school back home. It turns out that while Texas’ endless sunny days might have played a role, there are other reasons underpinning my winter hatred. Research suggests there are two kinds of people who tolerate the cold very well: indigenous Arctic groups, and men. And the more people are exposed to cold temperatures, the better they acclimate.

[Read: The Norwegian Town Where the Sun Doesn’t Rise]

Over the course of centuries, people who live in polar climates have evolved to be slightly more stout, and with shorter limbs, so they have less surface area, compared to their body mass, from which to lose heat. (Given my elk-like appendages, I assume whatever shtetl my Russian ancestors hailed from was not quite polar enough.) Other studies suggest polar peoples also tend to have more “brown fat,” which generates heat.

For several years, American anthropologists have been collaborating with Russian scientists to measure the basal metabolic rates, or BMRs, of the Yakut people of the Sakha Republic of Siberia. In Yakutsk, the Sakha’s capital city, winter temperatures hover around -30 degrees Fahrenheit. The basal metabolic rate is how much energy your body burns just to keep you alive, and a higher one reflects greater heat production. The scientists have found that Siberians have higher BMRs than people who live at lower latitudes, and that translates to them both needing more calories to stay alive and feeling warmer when it’s cold out. The Siberians’ BMRs rev up even higher as the temperature drops. According to one of the lead researchers on these studies, the Northwestern University anthropology professor William Leonard, this effect is consistent across other cold-climate populations.

Being a non-Siberian Russian can’t help me in this department. When Leonard and his colleagues compared the indigenous Siberians with non-indigenous Russians who just happened to live in the area, the Russians still had higher-than-average metabolic rates, but the indigenous Siberians’ was even higher. “With long-term, repeated exposure to cold, all humans have some capacity to increase their acclimatization to cold,” Leonard says. “But those populations with a deep evolutionary history seem to have genetic adaptation.”

The way the Siberians’ bodies generate these high metabolisms is by increasing their uptake of thyroid hormones, the chemicals released by a gland that sits in the neck. However, people who don’t have this adaptation shouldn’t just take synthetic thyroid hormones to try to replicate the effect, Leonard says. Doing so might confuse your thyroid so that it no longer functions normally. Indeed, Leonard says there are a lot of thyroid problems among the elderly Yakut, suggesting that not even this natural cold-weather adaptation is consequence-free.

On the plus side, having a higher BMR does make the Yakut somewhat less likely to gain weight. Compared to the tropical Bolivian populations Leonard has studied, the Yakut have better cardiovascular health, even though they tend to have stockier bodies than the Bolivians do and both groups’ diets have changed over the years.

BMR also helps explain why men—of all nationalities—tend to be better at tolerating the cold than women are. Women are often too cold at work because office-building temperatures are set to the men’s higher metabolic rates, according to a 2015 study on “female thermal demand,” which is my new term for the fights I start with my boyfriend over our apartment’s thermostat. Men, the study found, might be comfortable at temperatures as much as 5 degrees lower than women are.

[Read: The benefits of being cold]

Even if you don’t have the hearty genes of a Yakut, you can still learn to love—or at least tolerate—the cold. There are always “behavioral adaptations,” like putting on warm clothing or going for brisk walks. Ollie Jay, a professor in thermoregulatory physiology at the University of Sydney, once lived in Ottawa, one of the coldest capital cities on earth. “My first year there, I was miserable in the cold in the winter,” he told me. “The best thing I ever did was spend $7.50 on a fleece thing that could cover my nose, cheeks, and ears. It made such a difference to my level of discomfort.”

Jay told me that people can psychologically adapt to the temperature outside if they are exposed to it for about 10 days or more. That’s why those last few 40-degree March days feel so much warmer than the first 40-degree day of November. He and others have found that people who are exposed to the cold more often tend to shiver less and felt less cold, which suggests that their bodies got better at keeping them warm from the inside.

“As you become more acclimated to the cold, your body becomes more effective at delivering warm blood to the extremities, your core temperature goes up, and all that contributes to being more resistant to the cold,” Leonard told me.

That means the only cure for hating winter, unfortunately, is just more winter.

Article source here:The Atlantic